"You cannot leave behind what is always at your side."

Beckett paused, the soothing circles she'd been making with her thumb coming to a halt on her husband's hand. "Did you just make that up?"

He too froze, afraid that he'd just misspoken. "Yeah, why?"

The boys had said that Zhang was fast, but — quite simply — Beckett was faster. Castle barely had time to close his book before Beckett was straddling him and throwing the book to the side. "You are so much better than Patterson."

Castle huffed out a laugh as Beckett descended on him, breath catching in his throat when she began sucking at his pulse point and tugging down his pants. He grunted as she bit down on his neck, murmuring, "Someone's eager."

Beckett huffed out a laugh, victorious when his pants were around his ankles. "Can't help it that I want my husband so much."

Husband. It still thrilled them both, him especially when she did it in that voice.

Beckett had just begun to pull at his shirt — all the while keeping their mouths fused together — when he froze. "What?" she asked, pulling back enough so that they could make eye contact.

Castle sighed before motioning towards the door to their bedroom. "We left it open… again."

Beckett released a groan, which immediately turned into a squeal as Castle pushed them off of the bed. "Castle, what are you doing?"

In his head it had been a great idea: carry his wife across the room, shut the door with the force of their bodies like the first night they'd spent together, perfect. He'd neglected to remember the pajama pants around his ankles and sent them both tumbling.

They landed with a thump, Castle taking most of the hit, both breaking out in a fit of laughter. Beckett swatted at his chest. "That was not a good idea."

He shrugged, hair adorably mussed, and pulled her down on top of him. "I was trying to be romantic."

Beckett slanted her lips over his and began to grind her hips into his, grinning against his mouth at his already hard length. "Do you know what's not romantic?"

"Hmm?" Castle mumbles, too busy removing Beckett's shirt to really think about the question.

Beckett sighed and unclipped her bra, leaving her chest bare before him. "Alexis walking in on us."

Castle shook his head, drawing one of her breasts into his mouth and swirling his tongue around the stiff peak, before paying homage to its twin. "Not home. Sleeping over in her old dorm with friends."

"Your mother?"

Castle pulled down Beckett's shorts and underwear in one swift motion, leaving her bare before him. "Spending the night at Ben's place." Beckett giggled and tugged at his boxers, eyeing him hungrily as he did away with his own shirt. "So you, Mrs. Castle, can be as loud as you wish."

Beckett bit down on his neck just for that before brushing her lips along his sternum and taking his thick length in her hand, stroking and swirling her fingers around his tip.

They both sucked in a deep breath when Beckett brushed him through her wet folds, before gliding down in one fluid movement.

The couple released twin moans at the sensation, Beckett rolling her hips in an infinity symbol to accommodate the remainder of Castle.

She released a shiver as his hands began to stroke her thighs, the dark blue pools watching her face in complete adoration.

But it was when she planted her palms on the floor at either side of his head and began rocking that the moans truly echoed throughout the room.

This was her favorite mountain to climb. It was a summit that they both reached for together, worked for together.

"God, Kate. This never gets old." Castle brought her back to their moment, locking eyes as he pressed his thumb to her clit.

Beckett keened, releasing that throaty whine that meant she was close. And judging by the way Castle was meeting her thrust-for-thrust, he was nearing the edge too.

"What was on your list?"

Beckett grunted and grinded down harder before picking up her pace. Of course he just had to ask right then.

But when she looked down at those inquisitive blue eyes and ruffled brown hair, all she could see was a little boy, a mini Castle. "Baby."

"Yes?"

Beckett released a laugh, which turned into a gasp as he hit her back wall, the pleasure coiling even more in her abdomen. "No, Castle. A baby. I want a baby."

There was a moment where time seemed to stand still. Castle searched her face for any sign of hesitation, but all he saw was happiness… and nerves, but good nerves. They were the kind of nerves that a new mom should have.

Oh.

Castle pushed himself upwards, thrusting into Beckett as she settled in his lap. "Kate, you're gonna be a mom."

Beckett flipped her hair out of her face and leaned in for a long, open-mouthed kiss, before the need for release became too much.

"When?" Castle asked, but Beckett simply placed both of her hands on his shoulders, the cool feeling of her ring a pleasant contrast to the heat of his skin.

"Now."

That was all it took to spur Castle back into action, holding his wife close to him as they reached the edge together.

Beckett's walls began to flutter just as Castle spilled inside of her, the strength of both of their orgasms taking them by surprise.

Castle fell back onto the ground, hugging Beckett against his chest as they both came down from the high.

Neither was quite sure how long they stayed on the floor like that, still connected. It couldn't have been too long because the sweat on their skin had yet to dry when Beckett began undulating against Castle, pleased as he twitched inside of her.

"Think you can go for another round, Mr. Beckett?"

Castle scoffed, both at the name and her easy challenge. "I think I can go all night, Mrs. Castle." He sat up again, grimacing at the ache in his back. "As long as we take a break from the floor."

Beckett laughed and slid off of Castle, immediately missing the contact but aware that she would find it again soon enough.

She reached out her hand, giggling at the crack of Castle's knee and dragged him towards the bed, bottom lip pinned down by her teeth.

"Well we wouldn't want that, there's work to be done."